package com.sky.service.impl;

import com.sky.context.BaseContext;
import com.sky.dto.ShoppingCartDTO;
import com.sky.entity.Dish;
import com.sky.entity.Setmeal;
import com.sky.entity.ShoppingCart;
import com.sky.mapper.DishMapper;
import com.sky.mapper.SetmealMapper;
import com.sky.mapper.ShoppingCartMapper;
import com.sky.service.ShoppingCartService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.time.LocalDateTime;
import java.util.List;


@Service
@Slf4j
public class ShoppingCartServiceImpl implements ShoppingCartService {

    @Autowired
    private ShoppingCartMapper shoppingCartMapper;

    @Autowired
    private DishMapper dishMapper;

    @Autowired
    private SetmealMapper setmealMapper;

    /**
     * 添加购物车
     *
     * @param shoppingCartDTO
     */
    @Override
    public void addShoppingCart(ShoppingCartDTO shoppingCartDTO) {

        log.info("");

        //判断加入购物车中的商品是否已经存在了
        //select * from shopping_cart where user_id =? and setmeal_id = ?
        //select * from shopping_cart where user_id =? and dish_id = ? and dish_flavor = ?
        //使用动态sql，动态拼接条件就行
        ShoppingCart shoppingCart = new ShoppingCart();
        BeanUtils.copyProperties(shoppingCartDTO, shoppingCart);
        Long userId = BaseContext.getCurrentId();
        shoppingCart.setUserId(userId);
        List<ShoppingCart> list = shoppingCartMapper.list(shoppingCart);


        //如果存在，只要把数量加一
        if (list != null && list.size() > 0) {
            ShoppingCart cart = list.get(0);
            cart.setNumber(cart.getNumber() + 1);//update shopping_cart set number = ? where id = ?
            shoppingCartMapper.updateNumberById(cart);
        }


        //如果不存在，需要新插入一条数据
        else {
            //判断本次添加到购物车的是菜品还是套餐
            Long dishId = shoppingCartDTO.getDishId();
            if (dishId != null) {
                Dish dish = dishMapper.selectById(dishId);

                shoppingCart.setName(dish.getName());
                shoppingCart.setImage(dish.getImage());
                shoppingCart.setAmount(dish.getPrice());
            } else {
                Long setmealId = shoppingCartDTO.getSetmealId();
                Setmeal setmeal = setmealMapper.selectSetmealByid(setmealId);
                shoppingCart.setName(setmeal.getName());
                shoppingCart.setImage(setmeal.getImage());
                shoppingCart.setAmount(setmeal.getPrice());
            }
            shoppingCart.setNumber(1);
            shoppingCart.setCreateTime(LocalDateTime.now());

            //插入
            shoppingCartMapper.insert(shoppingCart);
        }

    }

    /**
     * 查看购物车
     *
     * @return
     */
    @Override
    public List<ShoppingCart> showShoppingCart() {
        Long userId = BaseContext.getCurrentId();
        ShoppingCart shoppingCart = ShoppingCart.builder().userId(userId).build();
        List<ShoppingCart> list = shoppingCartMapper.list(shoppingCart);
        return list;
    }

    /**
     * 清空购物车
     *
     * @return
     */
    @Override
    public void clean() {
        Long userId = BaseContext.getCurrentId();
        shoppingCartMapper.deleteByUserId(userId);
    }

    /**
     * 减少购物车商品数量
     *
     * @param shoppingCartDTO
     * @return
     */
    @Override
    public void sub(ShoppingCartDTO shoppingCartDTO) {
        //查询该商品的数量是否是1
        //如果是1 ，则直接删除该条记录
        ShoppingCart shoppingCart = ShoppingCart.builder().userId(BaseContext.getCurrentId()).build();
        BeanUtils.copyProperties(shoppingCartDTO, shoppingCart);
        List<ShoppingCart> list = shoppingCartMapper.list(shoppingCart);
        ShoppingCart cart = list.get(0);
        if(cart.getNumber() == 1) {
            shoppingCartMapper.delete(cart);
        }
        else {
            cart.setNumber(cart.getNumber() - 1);//update shopping_cart set number = ? where id = ?
            shoppingCartMapper.updateNumberById(cart);
        }
    }
}
